Sound amplifier



June; 21 1927.

' ATTORNEY H FISCHER SOUND AMPLIFIER Filed Feb. 4. 192a INVENTOR Patented dune 21, 1927.

P ATEN T-g OFFICE. Y

HEBMANN FISCHER, OF BOSTON, MASSACHUSETTS, .ASSIQITOR TO TOWER MANUFAC- TUBING CORPORATION, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAS SA cnusazrrs.

.soim n AMrLIrma.

Application filed February 4, 1926. Serial No. 85,828

The. object ofthe present invention is to I provide a sound amplifier comprising a resu onator and means for. operati'vely connecting the resonator and the diaphragm at a point or points spaced from the axis of the diaphragm. I have discovered that the con nection of a resonator,"as for example a cone type resonator, with a diaphragm through a needle or similar connection with thecentre of the diaphragm, acts to damp and prevent satisfacto'r vibration of the diaphragm. I have a so discovered that when the point or points of connection between the resonator and the diaphragm is substantially spacedfrom the centre of the latter, the damping isprevented. v

In the vibration of a diaphragm secured at its" periphery, the point of greatest vibra-- tion is at its arms, or in line with the magnet I poles. But the subjection of the diaphragm at that point to a load enablesthe maximum resistance of the load to the vibrations. The ideal condition in amplification is to secure maximum force with minimum degree of -movement in the vibrations of the dia the, force exerted on the diaphragm by the magnets operates the diaphragm as a lever relatively to the connecting member between i the resonator and the diaphragm, and thus whilstthe vibrations from the diaphragm are taken at a oint where they are substantially 1cm in ength of movement than at the centre, they have greater force and are better for proper vibration of the resonator. The invention will be used in connection with a diaphragm which mav be electrically vibrated as in the case of a radio loud speaker or a diaphragm which is mechanically vibrated as in the case of a phonogra h. v k e invention will be understood by ref-, erence to the accompanying drawing, in

Figure 1 illustrates in sectional side elevation a standard, aloud speaking unit and an embodiment of the invention as applied toa cone type resonator; F rgure-Qls a sectlonal elevat on. showing a modified form of th'e' inventioin applied to a cone type resonator, on the line 22, F igure 3;

' Figure 3 is a plan view of the structure illustrated. in Figure 1;

v Figure 4, is a view invertical'section of a modified form ofthe device on the line 44, Figure 5, and

Figure5is a plan view of the same; Figure 6 is axplan view 01' a blank combining a diaphragm with the connecting means for a resonator, and

Figure 7 is a vertical section through part of a cone type resonator showinga modified form of connection between the same and a diaphragm.

Referring to Figure 1, A represents a standard having at its upper end a chambet 1 to receive the magnet 2, the electrical. connections leading to the magnet elements passing. througlrthe standard to the base in the usual mannerQ The diaphragm acted upon by the .tnaguet is indicated at o clamped between an annular shoulder 4; of the standard top and a securing ring 5 which is threaded on the standard. Annularly arranged and spaced from the centre.

of the diaphragm 3 are a plurality ofwebs 6,whi'ch lead to a conical head 7 The webs 6 may be constructed separate from the diaphragm and head 7 and may be welded thereto, or they may be formed integrally'witlt one of the two members and brazed, soldered or otherwise secured to the second member. In Figure 6 I have shown the webs 6* as formed integrally with the diaphragm 3f.

Projecting at the apex of dome? is a threaded stem 8. This stem may pass through an aperture formed in the resonator I 9, a cap 10 may beplaced over the resonator and upon stem 8 and a nut 11 may be used to clamp the said associated members together so as to firmly hold dome 7 in contact with the resonator. I n orderv to prevent such edge vibration of the webs as will produce a noise, they may be covered with a' sound absorbing material such as rubber, felt or the like indicated at 12.- In the aforesaid eombination the d1aphragm-3 transmits its vibrations to the resonator 9 through conncctions which are spaced from the axial point of the diaphragm, a ring of connections being employed. Of course the form and arrangement of the connections may be widely varied from the construction shown in Figurel and the modifications illustrated in the drawings.- r

.In Figures 2 and 3 I have shown the connection intermediate the resonator and the diaphragm form as a ring 12 having transversely extending connecting members '13 for connection to the resonator and like members 14- for connection to the diaphragm.

In the modification illustrated in Figure 7, the connecting member is coniform and is provided at its point of minimum diamcl'er with a plurality of connection members 15 for apphcation to toe resonator 1G, and atits base with a plurality of connecting members 17 for application to" the diaphragm shown in dotted lines at 18. In the construction shown in- Figures 4 and 5 I apply a plurality of webs 19, which at their tops may be bent angularly as at 19 for connection to the resonator 20. it their base the webs may be formed with feetas at 21 for connection to the diaphragm 22 indicated in dotted lines.

It will'bc understood that the resonator may beformed in any desired shape. It maybe'flat, conical or other shape in cross section, and it may be round or rectangular o other peripheral shape. It will be also understood that any suitable number of connecting members may be employed intermediate the diaphragm and the resonator and thatithe'se connecting members may be formed as; pins, webs, rings and in various forms and shapes other than those illustrated in the drawings.

Having described my claim and desire to secure by Letters Patent is as toll ws; V V

1. In combination with a conitorm resonator having a free edge, of means for supporting and vibrating the resonator, comprising a diaphragm, means for vibrating the diaphragm and spaced Webs rigidly coninvention what I- nected to and extending transversely of the resonator.

2. In combination with a resonator of means for supporting and vibrating the same, comprising a diaphragm, having 'periphei ally projecting lingers, a plurality of the fingers being of major length and a plurality being of minor length, the major length fingers being bent at an angle and rigidly connected to the resonator, and a magnet device for vibrating the diaphragm, said device being adaptedto hold the diaphragm about its periphery by clamping the projections of minor length.

3. Sound amplifying apparatus, constructed in accordance with claim 2, in combination with sound absorbing means carried by the spaced projections of major length.

=1-. In sound amplifying apparatus, a diaphragm, a resonator. and means for operatively connecting the two, comprising spaced webs secured to the diaphragm near its pe riphery and extending transversely thereof.

5. In sound amplifying apparatus, a dia phragm, a magnet for vibrating the diaphragm, a resonator having a free edge, and means for both supporting and transmitting vibration to the resonator comprising a carrier for the resonator and a plurality of webs intermediate the diaphragm and the carrier and supporting the latter, the vibrations of the diaphragm being transmitted to the carrier through said Webs.

6. In sound amplifying apparatus, a diaphragm, a magnet for vibrating the diaphragm, a resonator having afree edge and means for both supporting and transmitting vibration to the resonator, comprising a rigid metallic carrier for the resonator having a marginal edge and means for supporting the carrier about its marginal edge, said means being connected with the diaphragm and said means transmitting the vibrations of the diaphragm to the carrier and the resonator.

In testimony whereof, have signed myname to this specification 7 HERMANN FISCHER. 

